Microalgae have long been valued as sustainable bioresources for biofuels and nutritional supplements, yet their transformation into sophisticated biomedical platforms represents one of the most promising frontiers in modern bioeconomy development. A comprehensive review published in the Journal of Bioresources and Bioproducts now establishes systematic pathways for converting these abundant photosynthetic organisms into functionalized composite bioproducts capable of precision diagnosis, targeted therapy, and integrated theranostics.
The inherent biological properties of microalgae provide an exceptional foundation for biomedical engineering. Their negatively charged surfaces facilitate molecular loading, specialized propulsion structures enable active movement, and abundant pigments deliver intense autofluorescence for imaging applications. However, direct utilization faces significant limitations including inadequate targeting specificity, suboptimal bioavailability, and restricted functionality under physiological conditions. The review addresses these constraints through detailed examination of controlled assembly strategies that integrate microalgae with polymers, nanoparticles, and therapeutic agents.
Four functionalization approaches define the current landscape. Physical modification leverages electrostatic adsorption and dehydration-rehydration strategies to load cargo while preserving cellular viability. Chemical functionalization employs covalent bonding and click chemistry for superior stability under harsh physiological conditions. Biotechnological methods including cell membrane coating and exogenous gene transformation enhance biocompatibility and enable programmed functionality. Hybrid approaches combining gel-based encapsulation with 3D bioprinting achieve complex architectural control for tissue-specific applications.
The diagnostic capabilities of functionalized microalgae span multiple imaging modalities. Their intrinsic autofluorescence enables label-free biological imaging and lesion localization, with Spirulina-based systems demonstrating particular promise for gastrointestinal tract visualization. Magnetic resonance imaging contrast enhancement has been achieved through magnetite nanoparticle encapsulation, while photoacoustic imaging benefits from polydopamine coatings that generate excellent signal intensity. Biosensing applications exploit microalgae environmental adaptability and fast response times, with diatom frustules serving as optical biosensing platforms and microfluidic integration enabling portable diagnostic devices.
Therapeutic applications demonstrate remarkable breadth. Chronic wound healing represents a primary success domain, where oxygen-generating microalgae address hypoxic conditions in diabetic ulcers. Living microecological hydrogels co-encapsulating Chlorella with beneficial bacteria create synergistic platforms that simultaneously relieve hypoxia and prevent pathogenic infection. Functionalized microalgae have demonstrated efficacy against radioactive radiation through antioxidant delivery, treatment of heavy metal poisoning via electrostatic adsorption, and emergency interventions for myocardial infarction and thrombotic stroke through targeted oxygen modulation and thrombolytic delivery.
Targeted drug delivery systems exploit species-specific structural advantages. Spirulina's helical morphology enables gastrointestinal retention and oral administration, while Chlamydomonas reinhardtii flagella provide autonomous propulsion for enhanced tissue penetration. Engineered microrobots achieve lung-targeted antibiotic delivery with three orders of magnitude bacterial reduction in infection models, and intra-articular injection systems demonstrate week-long retention for osteoarthritis treatment.
Perhaps most significantly, functionalized microalgae address the critical challenge of tumor hypoxia that limits conventional photodynamic, photothermal, and sonodynamic therapies. By providing sustained photosynthetic oxygenation, these systems reverse hypoxia-inducible factor signaling, enhance reactive oxygen species generation, and improve therapeutic efficacy while enabling multimodal combination approaches.
The review provides critical assessment of translational bottlenecks that must be resolved for clinical implementation. Immunogenicity arising from pathogen-associated molecular pattern recognition requires species selection and surface engineering strategies, with quantitative immune profiling essential for regulatory approval. Long-term biosafety considerations necessitate clear distinction between living biohybrid systems requiring biocontainment and inert templates evaluated as conventional biomaterials. Clinical translation demands scalable photobioreactor cultivation achieving batch-to-batch consistency, standardized critical quality attributes with defined acceptance criteria, and early regulatory engagement to establish appropriate evaluation frameworks for products spanning living therapies, drugs, and medical devices.
This comprehensive analysis establishes functionalized microalgae as a distinct class of renewable bioproducts with demonstrated capabilities across the full spectrum of biomedical applications. By systematically connecting functionalization strategies to performance outcomes and identifying concrete pathways for manufacturing scale-up and regulatory approval, the review provides actionable guidance for advancing these sustainable materials from proof-of-concept studies to clinical reality.
See the article:
DOI
https://doi.org/10.1016/j.jobab.2026.100249
Original Source URL
https://www.sciencedirect.com/science/article/pii/S2369969826000216
Journal
Journal of Bioresources and Bioproducts
Literature review
Not applicable
Functionalized Microalgae as Emerging Composite Bioproducts for Biomedical Applications: Design, Fabrication and Prospects
27-Mar-2026